Guide to Bridge March 2016 Bridge Division
Table of Contents About this Guide... 3 Pretensioned Concrete I-Beam Bridge... 5 Pretensioned Concrete I-Girder Bridge... 6 Pretensioned Concrete Slab Beam Bridge... 10 Pretensioned Concrete Decked Slab Beam Bridge... 15 Pretensioned Concrete Box Beam Bridge... 19 Pretensioned Concrete Spread Box Beams (X-Beams) Bridge... 23 Cast-in-Place Concrete Slab and Girder (Pan Form) Bridge... 27 Cast-in-Place Concrete Slab Span Bridge... 30 Steel Beam Bridge... 33 Guide to Bridge TxDOT 03/2016 2
About this Guide Purpose & Audience This document provides quick-reference information to guide bridge designers who are working for the Texas Department of Transportation (TxDOT) in the use of bridge standard drawings, which are posted on the TxDOT web site: http://www.dot.state.tx.us/insdtdot/orgchart/cmd/cserve/standard/bridge-e.htm. Document History This Document is subject to revision as new guidelines are documented and as conditions, experience, and research data warrant. Revisions are summarized in the following table, and text that has been added or changed since the previous version in green. Publication Date June 2003 November 2003 August 2004 January 2005 October 2005 January 2006 March 2007 April 2008 Summary of Changes Initial release: Published guidelines for use of standard drawings for prestressed concrete slab beams. Revision adding information on castin-place concrete slab span bridge standard drawings. Revision updating existing information and adding information on steel beam bridge standard drawings. Revision adding information on prestressed concrete I-beam bridge standard drawings. Revision adding information on concrete slab and girder (pan form) span bridge standard drawings. Revision adding information on prestressed concrete double-t beam bridge standard drawings. Revision adding information for prestressed concrete box beams standard drawings. Revision adding information on decked slab beams. Guide to Bridge TxDOT 03/2016 3
September 2010 June 2011 August 2011 September 2013 October 2015 March 2016 Revision adding information regarding I-girder bridge standard drawings. Revision adding information regarding X-beam bridge standard drawings. Revision deleting information for double-t beams and retiring standard drawings of same effective August 2011. Revision amending the Drawing Features of the Concrete Slab and Girder (Pan Form) Bridge. Revision amending the Description of Component of the Prestressed Concrete Slab Beam Bridge. Revision to add new miscellaneous standard drawings. Revision adding restrictions on use. Revision retiring I-Beam drawings effective November 2014. Revision to I-Girder standard drawings increasing slab depth from 8 in. to 8 ½ in. Revision to Box Beams to include removal of BBSDO, SBBO, BBRAO, BBPT & removal of ACP (Asphaltic Concrete pavement). Revision adding information to accommodate T221P, T224 and SSPC standard drawings. Feedback Any questions or comments on the content contained in this document can be directed to the Director of the Bridge Division, Texas Department of Transportation. Guide to Bridge TxDOT 03/2016 4
Pretensioned Concrete I-Beam Bridge Note All standard drawings for I-Beams are retired effective November 2014. Guide to Bridge TxDOT 03/2016 5
Pretensioned Concrete I-Girder Bridge Advantages/ Usefulness Drawing Location Drawing Features Needed for Pretensioned concrete I-Girders are useful for bridges with skewed substructure, when substructure depth is not restricted, and where future widening is anticipated. Pretensioned concrete I-Girder bridges cost less than all other standard bridge types. IG prefixes Website: http://www.dot.state.tx.us/insdtdot/orgchart/cmd/cserve/standard/ bridge-e.htm#igirders Designed for HL93 live load in accordance with AASHTO LRFD Bridge Design Specifications. accommodate: Tx28, Tx34, Tx40, Tx46, Tx54, and Tx62 24-, 28-, 30-, 32-, 38-, 40-, and 44-ft. roadway widths 0-, 15-, 30-, and 45-degree skew angles. Span lengths of 40 ft. through 135 ft. in 5 ft. increments. Not all girder types accommodate all span lengths. Abutment header slopes of 2:1 and 3:1. Most standard rail types. Roadway surface is a cast-in-place concrete slab with 8 ½ -in. depth. Details are provided to construct 2 or 3 span units with slabs continuous over interior bents. Using units reduces the number of expansion joints. support these foundation options: Drilled shafts (36-and 42-in) Multi-pile footings Prestressed concrete piling (18-,20-,24-in) Steel H-piling (HP 14x117 and HP 18x135) provide details for drilled shafts and multi-pile footings only for interior bents for Tx62 girders. Seven standard drawings are provided to use with customized bridge plans. IGSD Roadway specific Prestressed Concrete I-Girder standard drawing AIG Girder, roadway and skew specific Abutment standard drawings Guide to Bridge TxDOT 03/2016 6
(Continued) Needed for Additional Needed to Complete BIG Girder, roadway and skew specific Interior Bent standard drawing or; BTIG for interior Trestle Bent standard drawings SIG Girder, roadway and skew specific span standard drawing IGCS Continuous Slab details standard drawing (only if using multispan units with slab continuous over interior bents). IGD Prestressed Concrete I-Girder Details standard drawing. IGEB Elastomeric Bearing and Girder End Details standard drawing. IGMS Miscellaneous Slab Details standard drawing IGTS Thickened Slab End details standard drawing Bridge Layout Summary of Estimated Quantities (if not shown on Bridge Layout) Drawing with bearing seat elevations (Recommended, see Special Considerations ) Bridge railing detail drawings Expansion joint detail drawings, if not using Type A joints. BAS-A or BAS-C Bridge Approach Slab, if applicable. BD-3 Bridge Deck Drain Details, if applicable. Details for drainage pipe are not provided and must be developed. BL Bridge Lighting Details standard drawing, if applicable. BMCS Bridge Mounted Clearance Sign standard drawing, if applicable. BPBW Bridge Protective Beam Wrap, if applicable. CP Prestressed Concrete Piling standard drawing, if piling is used for foundations. CRR Concrete Riprap and Shoulder Drain standard drawing, if applicable. CSAB Cement Stabilized Abutment Backfill standard drawing, if applicable. FD - Common Foundation Details standard drawing IGFRP GFRP Slab Top Mat Reinforcement, if applicable. IGSK I-Girder Shear Key standard drawing, if applicable MEBR(C) Minimum Erection and Bracing Requirements standard drawing ODSR Optional Drilled Shaft Reinforcing standard drawing. Verify applicability prior to use. PBC-RC or PBC-P Precast Bent Cap Option standard drawing. (RC) for round columns and (P) for piles PCP & PCP-FAB Prestressed Concrete Panel standard drawings PMDF Permanent Metal Deck Form standard drawing SRR Stone Riprap, if applicable. SSPC Steel Sheet Piling Corner Details standard drawing, if applicable Guide to Bridge TxDOT 03/2016 7
Restrictions on Use of Do not change girder type (for example, Tx28 to Tx40) within a bridge; transition bent details are not provided. Maximum allowed column height, allowed exposed pile height, and maximum allowed pile loads are listed on bent details. Do not use rail types T66, T80HT, T80SS, C412, C66, or T224. Their width or weight precludes their use on standard roadway width spans. Do not change skew angle within a bridge. Use issued substructure details only with issued span details. The maximum number of spans per unit is three, and the maximum unit length cannot exceed the limits shown on standard drawing IGCS. Some unit lengths are too great to use sealed or open armor joints and Type A joints. Do not use single-sided crash cushions (see Design Division standard drawing SSCC-03A) with abutment wingwalls lengths less than 7 ft. do not accommodate raised sidewalks and medians or rails not on edge of slab. If adding a raised sidewalk, median or rail, check standard drawing for additional loading. NOTE: Some restrictions may be overcome by modifying the standard drawings with appropriate additional details and information. Denote modified details as MOD in the title block, and clearly indicate which drawings must be signed, sealed and dated by a registered Professional Engineer. Special Considerations If girder slope exceeds 5%, standard drawing IGED requires beveled steel sole plates be used at bearings. Sole plates add 1-inch to the section depth which will need to be accounted for in bearing seat elevation calculations. Modify abutment standard for the extra section depth accordingly, if applicable. As a check to the Contractor s calculated elevations, provide bearing seat elevations in the plan if a roadway vertical curve is located on the structure (recommended). If an adjustment is made to the section depth (to accommodate a sag vertical curve), note the section depth adjustment used along with the bearing seat elevations. Spreadsheet STD-BRG.xls, available from the Bridge Division, is a tool to help calculate and generate bearing seat elevations. It also generates girder slopes, which can be provided with the bearing elevations to aid the bearing pad fabricator. Guide to Bridge TxDOT 03/2016 8
(Continued) Special Considerations Specific Bridge Layout Requirements If the presence of a roadway vertical curve forces a haunch depth greater than 3 ½ in. at any point on a girder, reinforce the haunch as instructed by standard drawing IGMS. If Prestressed Concrete Panels are used as a forming option, find this haunch reinforcement on standard drawing PCP. Do not use open bridge rails such as T223, T552, etc. when frequent use of de-icing agents is anticipated. If deck drainage is desired and de-icing agent use is predicted, use the drain details shown on standard IGMS. Locate the drain locations on the Bridge Layout (no closer than 4 ft. from centerline of the substructure caps.) On substructure standard drawings, dowel bars D are noted to be excluded at ends of units. Therefore, if continuous slab units are indicated on the bridge layout and standard drawing IGCS is included in the plans, do not use dowels at unit end (expansion joint locations). If using interior trestle bents (standard drawing prefix BTIG), note limitations on pile load and exposed pile heights when selecting a pile type and size. Quantities provided for reinforcing steel weight and slab concrete volume are not bid items. They are provided for contractor s information only. Adjust bent concrete quantities as needed for column heights shown on the Bridge Layout. Adjust abutment concrete quantities if not using approach slabs. See substructure standard drawings for guidance. Label all girder ends with a D except when using multi-span units. With units, do not label girder ends D at expansion joint locations. List unit lengths if not locating expansion joints at each bent. For continuous slabs, see details and notes on span standard drawings and standard IGCS; two- or three-span units are conditionally permitted. Verify that column or exposed pile heights do not exceed values listed on bent standard drawings. These maximum heights must be evaluated by the Engineer in areas of soft soil or where scour is anticipated. Indicate abutment wingwall foundations if required. See Abutment standard drawings for wingwall foundation requirements based on girder type and header slope. Recommended expansion joints in order of preference are 4-in. sealed expansion joints (see standard drawing SEJ-A), sealed armor joints (see standard drawing AJ), and Type A joints (see standard drawing IGMS). Type A joints and open armor joints are not recommended for On-System structures. Type A joints are recommended for bridges with low traffic volumes only. Do not place Type A joints more than 100 ft. apart for proper joint performance. Guide to Bridge TxDOT 03/2016 9
Pretensioned Concrete Slab Beam Bridge Advantages/ Usefulness Drawing Location Drawing Features Pretensioned concrete slab beams are useful for bridges needing shallow superstructures and fast construction. Pretensioned concrete slab beam bridges cost more than pretensioned concrete I-Girder bridges and cost less than pretensioned concrete box beam bridges. Construction is similar to pretensioned concrete box beam bridges. Slab beams do not have shear keys therefore must be topped with a cast-in-place concrete slab to ensure that beams act in unison. PSB prefixes. Web site: http://www.dot.state.tx.us/insdtdot/orgchart/cmd/cserve/standard/br idge-e.htm#slabbeams Designed for HL93 live load in accordance with AASHTO LRFD Bridge Design Specifications. accommodate 24-, 28-, and 30-ft. roadway widths. 0-, 15-, and 30-degree skew angles. With SB12 beams, drawings accommodate span lengths of 25 ft. through 40 ft. in 5-ft. increments. Maximum superstructure depth with SB12 beams is 18.5 in., which accounts for beam camber and dead-load deflection. With SB15 beams, drawings accommodate span lengths of 25 ft. through 50 ft. in 5-ft. increments. Maximum superstructure depth with SB15 beams is 22 in., which accounts for beam camber and dead-load deflection. Abutment header slopes of 2:1 and 3:1 Most standard rail types Roadway surface is a cast-in-place concrete slab with a 5-in. minimum depth. Details are provided to construct 2 or 3 span units with slabs continuous over interior bents. Using units reduces the number of expansion joints. support these foundation options: Drilled shafts (24-in) Prestressed concrete piling (16- and 18-in.) Steel H-piling (HP14x73 and HP14x117). Seven standard drawings are provided to use with customized bridge plans. Guide to Bridge TxDOT 03/2016 10
Needed for Additional Needed to Complete Restrictions on Use of APSB - Roadway and skew-specific Abutment standard drawing. Some skewed abutment standard drawings are foundation-specific (for example, drilled shafts and pilings). BPSB Roadway and skew-specific Interior Bent drawing SPSB Roadway and skew-specific span standard drawing. PSB Appropriate Prestressed Concrete Slab Beam standard drawing PSBEB Elastomeric Bearing standard drawing PSBRA Rail Anchorage standard drawing PSBSD Prestressed Concrete Slab Beam Design standard drawing Bridge Layout Summary of Estimated Quantities (if not shown on the Bridge Layout). Bridge railing detail drawings Expansion joint detail drawings, if not using Type A joints. BAS-A or BAS-C Bridge Approach Slab standard drawing, if applicable. BMCS Bridge Mounted Clearance Sign standard drawing, if applicable. BPBW Bridge Protective Beam Wrap, if applicable. CP Prestressed Concrete Piling standard drawing if piling is the foundation type. CRR Concrete Riprap and Should Drains standard drawing, if applicable. CSAB Cement Stabilized Abutment Backfill standard drawing, if applicable. FD Common Foundation Details standard drawing ODSR Optional Drilled Shaft Reinforcing standard drawing. Verify applicability prior to use. PBC-RC or PBC-P Precast Bent Cap Option standard drawing. (RC) for round columns or (P) for piles. SRR Stone Riprap, if applicable. SSPC Steel Sheet Piling Corner Details standard drawing, if applicable Do not change roadway cross slope on bridges. Roadway vertical curves may not be used on bridges with skewed supports. Calculations required for determining top-of-cap elevations and bearing pad dimensions with these conditions are beyond the scope of these drawings. Roadway vertical curves are allowed on bridges without skewed supports. Skew angle is limited to 30 degrees. Do not change beam type (such as SB12 to SB15) within a bridge; transition bent details are not provided. Maximum allowed column height, allowed exposed pile heights, and maximum allowed pile loads are listed on bent details. Guide to Bridge TxDOT 03/2016 11
(Continued) Restriction on Use of Do not use a rail type that is not listed on the PSBRA standard drawing. Rail anchorage details for rails not located at bridge edges are not provided. T411 and C411 rail types may not be used with supports skewed 30 degrees. The end post (adjacent to the abutment) may be too narrow. Do not use multi-pile footings shown on standard drawing FD. Do not use standard drawing BL Do not change skew angle within a bridge. Use issued substructure details only with issued span details. The maximum number of spans per unit is three. Bearing pads shown on standard drawing PSBEB are restricted to one-, two-, and three-span units with 25-ft. minimum, 50-ft. maximum span lengths. Do not use single-sided crash cushions (see Design Division standard drawing SSCC-03A) with abutment wingwall lengths less than 7 ft. Do not use rail types T66, T80HT, T80SS, C412, C66, T221P, or T224. Their width or weight precludes their use on standard roadway spans. do not accommodate raised sidewalks and medians or rails not on edge of slab. If adding a raised sidewalk, median or rail, check standard drawing for additional loading. NOTE: Some restrictions may be overcome by modifying the standard drawings with appropriate additional details and information. Denote modified details as MOD in the title block, and clearly indicate which drawings must be signed, sealed and dated by a registered Professional Engineer. Special Considerations If a roadway vertical curve is used, adjust section depths listed on span details as noted on non-skewed span standard drawings. Section depth adjustment does not justify standard drawing modification. Beveling bearing pads to match beam slope will result in non-parallel pad and beam surfaces for skewed bridges. Bearing pads beveled in both directions are necessary to provide parallel pad and beam surfaces with skewed bridges. However, fabrication of such pads is impractical. Given the small area of the pads and the nearly parallel surfaces, pads beveled to match beam slope should accommodate small mismatches. Spreadsheet STD-BRG.xls, available from the Bridge Division, is a tool to help calculate and generate top of cap elevations and bearing pad tapers. Quantities provided for reinforcing steel weight and slab concrete volume are not bid items. They are for Contractor s information only. Adjust bent concrete quantities as needed for column heights shown on the Bridge Layout. Adjust abutment concrete quantities if not using approach slabs. See substructure standard drawings for guidance. Guide to Bridge TxDOT 03/2016 12
(Continued) Special Considerations Specific Bridge Layout Requirements Earwalls are incorporated into abutments and interior bents for lateral restraint of the superstructure: exterior beams bear against the earwalls with a ½-inch layer of preformed bituminous fiber material between beam and earwall. It may be difficult to ensure that beams fit within the earwalls or bear against them due to fabrication and construction tolerances and lateral translation of beams on neoprene bearings resulting from roadway cross-slope. Therefore, substructure details provide a permissible construction joint so that earwalls can be cast after beams are set, using the beams as a form. If earwalls are cast prior to beam placement, their inside face must be cast perpendicular to the top of cap to ensure parallelism with beams. Do not use Asphalt Concrete Pavement (ACP) topping for slab beams in lieu of a 5-inch concrete slab because of the discrete, open joints between beams. A 5-inch minimum depth concrete slab for the beams is required to provide adequate rail anchorage and expansion joint hardware. Foam backer rods may be placed between beams to act as a form for the slab. Backer rod diameter should be 125% of the joint opening. T631 and T631LS cast-in-place anchorage details provided on standard drawing PSBRA are based on the maximum X dimension (slab thickness at CL of bearing) listed on standard span drawings, 7 in. If slab thickness exceeds 7 in. at any point along the beam, modify length of anchor bolt accordingly. Beam ends located at expansion joints (other than Type A joints) must have a blockout to provide room for expansion joint anchors. See standard drawings with a PSB prefix for blockout details. Slab forms may not rest on tops of beams (see Detail A on span standard drawings). Sheet metal, for example, would act as a bond breaker and could result in reflective cracking. Do not use open bridge rails such as T223, T552, etc. when frequent use of de-icing agents is anticipated. Indicate beam type (SB12 or SB15). List unit lengths if not locating expansion joints at each bent. For continuous slabs, see details and notes on span standard drawings; two- or three-span units are permitted. Verify that column or exposed pile heights do not exceed values listed on the bent standard drawings. These maximum heights must be evaluated by the Engineer in areas of soft soil or where scour is anticipated. Recommended expansion joints in order of preference are Type A joints (shown on span standard drawings), 4-in. sealed expansion joints (standard drawing SEJ-A), and armor joints (standard drawing AJ). Do not place Type A joints more than 100 ft. apart for proper performance. Type A joints are recommended for bridges with low traffic volumes only. Guide to Bridge TxDOT 03/2016 13
(Continued) Specific Bridge Layout Requirements Provide information on the layout about pad arrangements other than those shown on the PSBEB standard drawing. Note roadway width as nominal in Plan View and Typical Section for 28- and 30-ft. roadway structures. Overall width in Plan view and Typical Section must be shown as actual overall width for example, 32.125 ft. for 30-ft. roadway structures. Guide to Bridge TxDOT 03/2016 14
Pretensioned Concrete Decked Slab Beam Bridge Advantages/ Usefulness Drawing Location Drawing Features Needed for Pretensioned concrete decked slab beams are useful for bridges requiring shallow superstructure and fast construction. Because Pretensioned concrete decked slab beams are adjacently placed, they cannot be used for bridges with horizontal curves or flares. Pretensioned concrete decked slab beams are topped with a 2-in. asphaltic concrete pavement (ACP) to provide a smooth roadway surface over the cambered beams. DSB prefixes. Web site: http://www.dot.state.tx.us/insdtdot/orgchart/cmd/cserve/standard/br idge-e.htm#deckedslabbeam Designed for HL93 live load in accordance with AASHTO LRFD Bridge Design Specifications. accommodate Two beam depths (20- and 23-in.) each in three nominal widths (6.5-, 7.5-, and 8.0-ft.). 24-ft., 28-ft. and 30-ft. roadway widths. 0-, 15-, and 30-degree skew angles Span lengths of 30 ft. through 60 ft., in 5 ft. increments. Not all beam types accommodate all span lengths. A beam topping of 2-in. minimum asphaltic concrete pavement. Abutment header slops of 2:1 and 3:1. Most standard rail types. support these foundation options: Drilled shafts (30-in) Prestressed concrete (16-, 18-, and 20-in.) Steel H-piling (HP14x73, HP14x117, and HP18x135). Four standard drawings are provided to use with custom bridge plans DSBSD Roadway specific Decked Slab Beam Designs standard drawing ADSB Roadway-specific Abutment standard drawings BDSB Roadway-specific Interior Bent standard drawing SDSB Roadway-specific Span standard drawing DSBD Decked Slab beam detail standard drawing DSBEB Elastomeric Bearing standard drawing DSBRA Rail Anchorage standard drawing Guide to Bridge TxDOT 03/2016 15
Additional Needed to Complete Restrictions on Use of Bridge Layout. Summary of Estimated Quantities (if not shown on the bridge layout) Bridge railing detail drawings BMCS Bridge Mounted Clearance Sign standard drawing, if applicable. BPBW Bridge Protective Beam Wrap standard drawing, if applicable CP Prestressed Concrete Piling standard drawing, if concrete piling is used for foundations CRR Concrete Riprap and Shoulder Drains standard drawing, if applicable. CSAB Cement Stabilized Abutment Backfill standard drawing FD Common Foundation Details standard drawing. ODSR Optional Drilled Shaft Reinforcing standard drawing. Verify applicability prior to use. PBC-RC or PBC-P Precast Bent Cap Option standard drawing. (RC) for round column or (P) for piles. SRR Stone Riprap, if applicable. SSPC Steel Sheet Piling Corner Details standard drawing, if applicable Do not use for bridges requiring both skew and a vertical curve. Do not change roadway cross slope on bridges. Do not change skew angle within a bridge. Use issued substructure details only with issued span details. Do not change beam depths within a bridge (for example, a 6DS20 to a 6DS23); transition bent details are not provided. Maximum allowed column height, allowed exposed pile heights, and maximum allowed pile loads are listed on bent details. Do not use a rail type that is not listed on the DSBRA standard drawing. drawings BAS-C and BAS-A for bridge approach slabs do not apply. Rail anchorage details for rails not located at bridge edges are not provided. Do not use multi-pile footings shown on standard drawing FD. Do not use sealed expansion joints shown on standard drawing SEJ-A or SEJ-S(O) or armor joints shown on standard drawing AJ. Do not use Type A joints as described in Item 422, Concrete Superstructures. Do not use single-sided crash cushions (see Design Division standard drawing SSCC-03A) with abutment wingwalls lengths less than 7 ft. Do not use tail types T66, T80HT, T80SS, C412, C66, T221P, or T224. Their width or weight preclude their use on standard roadway width spans. do not accommodate raised sidewalks and medians or rails not on edge of slab. If adding a raised sidewalk, median or rail, check standard drawing for additional loading. Guide to Bridge TxDOT 03/2016 16
(Continued) Restrictions on Use of NOTE: Some restrictions may be overcome by modifying the standard drawings with appropriate additional details and information. Denote modified details as MOD in the title block, and clearly indicate which details were modified in the standard drawing sheet. All modified standard drawings must be signed, sealed, and dated by a registered Professional Engineer. Special Considerations Do not use decked slab beams for skewed bridges that require a roadway vertical curve or for bridges requiring a cross-slope transition. It is not possible to develop the necessary roadway surface with decked slab beams and simultaneously provide the required parallelism of bent and abutment bearing surfaces for each beam with the aforementioned geometry. A skewed bridge without a roadway vertical curve is acceptable. Likewise, vertical curves are acceptable for nonskewed bridges. Top of backwall elevation is set equal to top of beam elevation, with the ACP topping being placed over both to achieve finished grade elevation. Decked slab beams can be topped with a two course surface treatment without being followed up by a 1.5 to 2.0 in. layer of hot mixed asphaltic concrete. This is considered acceptable only on low design speed, low volume off-system roads where the beam camber s detrimental effect on ride quality is considered acceptable by the Engineer. The standard drawings do not accommodate this roadway surface modification. A modification to the standard expansion joint detail would be required with this type of construction. Some roadway widths will require two or more different widths of decked slab beams in the cross-section. At joints between beams of different widths, a camber differential will exist up to 0.5 in. approximately. In this case, the 2 in. ACP overlay is considered mandatory for the roadway surface. Do not use open bridge rails such as T223, T552, etc. when frequent use of de-icing agents is anticipated. Quantities provided for reinforcing steel weight are not bid items. They are provided for Contractor s information only. If roadway vertical curve is used, adjust section depths listed on span details. Section depth adjustment does not justify standard drawing modification. Bearing seats are not used on decked slab beam bridges; the pads sit directly on the top of the bent cap. Top of cap elevations must be provided at the points coinciding with the outer edge of exterior beams at centerline of bearing and at all intermediate points where a change in cap slope occurs. Spreadsheet STD-BRG.xls, available from Bridge Division, is a tool to help calculate the general top of cap elevations and bearing pad Guide to Bridge TxDOT 03/2016 17
tapers. (Continued) Special Considerations Specific Bridge Layout Requirements Adjust bent concrete quantities as needed for column heights shown on the Bridge Layout. See substructure standard drawings for guidance. Earwalls are incorporated into abutments and interior bents for lateral restraint of the superstructure: exterior beams bear against the earwalls with a ½-inch layer of preformed bituminous fiber material between beam and earwall. It may be difficult to ensure that beams fit within the earwalls or bear against them due to fabrication and construction tolerances and lateral translation of beams on neoprene bearings resulting from roadway cross-slope. Therefore, substructure details require earwalls be cast after beams are set, using the beams as a form. To limit negative effects of pad lateral deflection due to beam dead load, erect first the beams adjacent to crown point or at high side of single cross slope. Fabric underseals complying with Item 356, Fabric Underseal, are required to control or mitigate reflective cracking. Rail anchorage details provided on standard drawing DSBRA are based on the maximum X dimension on span standard drawings. Expansion joints are required at the end of each span. Use only the joint shown on standard drawings with prefix SDSB. There are no units with decked slab beams. Verify that column or exposed pile heights do not exceed values listed on bent standard drawings. These maximum heights must be evaluated by the Engineer in areas of soft soil or where scour is anticipated. Indicate beam type, e.g. 6DS20, 8DS23, etc. Guide to Bridge TxDOT 03/2016 18
Pretensioned Concrete Box Beam Bridge Advantages/ Usefulness Drawing Location Drawing Features Needed for Pretensioned concrete box beams are useful for bridges requiring shallow superstructure and fast construction. Because pretensioned concrete box beams are adjacently placed, they cannot be used for bridges with horizontal curves or flares. Pretensioned concrete box beams are topped with 5-in. cast-in-place slab. Pretensioned concrete box beams are typically higher in cost than other beams because of the complexity of fabrication. BB prefixes. Web site: http://www.dot.state.tx.us/insdtdot/orgchart/cmd/cserve/standard/bri dge-e.htm#boxbeams Designed for HL93 live load in accordance with AASHTO LRFD Bridge Design Specifications. Accommodate: Four beam depths (20-, 28-, 34-, and 40-in.) each in two nominal widths (4-ft. and 5-ft.). The standard 24- and 30-ft. roadways use both 4- and 5-ft. wide beams. 24-, 28-, and 30-ft. roadway widths Span lengths of 30 ft. through 100 ft., in 5 ft. increments. Not all beam types accommodate all span lengths. Abutment header slopes of 2:1 and 3:1 Most standard rail types. Roadway surface is a cast-in-place concrete slab with a 5-in. minimum depth. Details are provided to construct 2 or 3 span units with slabs continuous over interior bents. Using units reduces the number of expansion joints. support these foundation options: Drilled shafts (30-in) Prestressed Concrete Piling (16-, 18-, 20-in.) Steel H-piling (HP14x73, HP14x117, and HP18X135) Nine standard drawings are provided to use with customized bridge plans. BBSDS Beam and roadway-specific Box Beam Designs standard drawing. ABB Roadway-specific Abutment standard drawings Guide to Bridge TxDOT 03/2016 19
(Continued) Needed for Additional Needed to Complete Restrictions on Use of BBB Roadway specific Interior Bent standard drawing SBBS Beam and roadway-specific span standard drawings. BB Appropriate Box Beam details standard drawings BBEB Elastomeric Bearing standard drawing BBRAS Topping-specific rail anchorage standard drawing. Bridge Layout Summary of Estimated Quantities (if not show on the Bridge Layout). Bridge railing details drawings Expansion joint detail drawings, if not using Type A joints. Type A joints recommended for low volume traffic only. BAS-A or BAS-C Bridge Approach Slab standard drawings, if applicable. BMCS Bridge Mounted Clearance Sign drawing, if applicable BPBW Bridge Protective Beam Wrap standard drawing, if applicable. CP Prestressed Concrete Piling standard drawing, if pilling is used for foundations CRR Concrete Riprap and Should Drains standard drawing, if applicable CSAB Cement Stabilized Abutment Backfill standard drawing, if applicable FD Common Foundation Details standard drawing ODSR Optional Drilled Shaft Reinforcing standard drawing. Verify applicability prior to use. PBC-RC or PBC-P Precast Bent Cap Option standard drawing. (RC) for round columns or (P) for piles. SRR Stone Riprap, if applicable. SSPC Steel Sheet Piling Corner Details standard drawing, if applicable Use drawings only for bridges without skews. Do not change roadway cross slope on bridges. Use issued substructure details only with issued span details. Do not change beam depths within a bridge (for example, a 5B28 to a 5B34); transition bent details are not provided. Do not change skew angle within a bridge. Maximum allowed column height, allowed exposed pile heights, and maximum allowed pile loads are listed on bent details. Do not use a rail type that is not listed on the rail anchorage standard drawing, BBRAS. Rail anchorage details for rails not located at bridge edges are not provided. Do not use multi-pile footings shown on standard drawing FD. Guide to Bridge TxDOT 03/2016 20
(Continued) Restrictions on Use of The maximum number of spans per unit is three. Some unit lengths are too great to use sealed or open armor joints and Type A joints. do not accommodate raised sidewalks and medians or rails not on edge of slab. If adding a raised sidewalk, median or rail, check standard drawing for additional loading. Do not use rail types T66, T80HT, T80SS, C412, C66, T221P, or T224. Their width or weight precludes their use on standard roadway width spans. Do not use single-sided crash cushions (see Design Division standard drawing SSCC-03A) with abutment wingwall lengths less than 7 ft. NOTE: Some restrictions may be overcome by modifying the standard drawings with appropriate additional details and information. Denote modified details as MOD in the title block, and clearly indicate which details were modified in the standard drawing sheet. All modified standard drawings must be signed, sealed, and dated by a registered Professional Engineer. Special Considerations Quantities provided for reinforcing steel weight are not bid items. They are provided for Contractor s information only. If roadway vertical curve is used, adjust section depths listed on span details. Section depth adjustment does not justify standard drawing modification. Bearing seats are not used on box beam bridges; the pads sit directly on the top of the cap. Top of cap elevations must be provided at the points coinciding with the outer edge of exterior boxes at centerline of bearing and at all intermediate points where a change in cap slope occurs. Spreadsheet STD-BRG.xls, available from the Bridge Division, is a tool to help calculate and generate top of cap elevations and bearing pad tapers. Adjust bent concrete quantities as needed for column heights shown on the Bridge Layout. Adjust abutment concrete quantities if not using approach slabs. See substructure standard drawings for guidance. Earwalls are incorporated into abutments and interior bents for lateral restraint of the superstructure: exterior beams bear against the earwalls with a ½-inch layer of preformed bituminous fiber material between beam and earwall. It may be difficult to ensure that beams fit within the earwalls or bear against them due to fabrication and construction tolerances and lateral translation of beams on neoprene bearings resulting from roadway cross-slope. Therefore, substructure details require earwalls be cast after beams are set, using the beams as a form. To limit negative effects of pad lateral deflection due to beam dead load, erect first the beams adjacent to crown point or at high side of Guide to Bridge TxDOT 03/2016 21
(Continued) Special Considerations Specific Bridge Layout Requirements single cross slope. Beam ends located at expansion joints (other than Type A joints) must have a blockout to provide room for expansion joint anchors. See standard drawings with a BB prefix for blockout details. When widening existing structures, like topping is recommended. T631 and T631LS cast-in-place anchorage details provided on standard drawing BBRAS are based on the maximum X dimension (slab thickness at CL of bearing) of 10 in. If slab thickness exceeds 10 in. at any point along the beam, modify length of anchor bolt accordingly. Do not use open bridge rails such as T223, T552, etc. when frequent use of de-icing agents is anticipated. List unit lengths if not locating expansion joints at each bent. See span details for limits on unit length. Verify that column or exposed pile heights do not exceed values listed on bent standard drawings. These maximum heights must be evaluated by the Engineer in areas of soft soil or where scour is anticipated. Recommended expansion joints in order of preference are 4-in. sealed expansion joints (see standard drawing SEJ-A), sealed armor joints (see standard drawing AJ), and Type A joints (see standard box beam span drawings SBBS). Type A joints and open armor joints are recommended for low volume roads only. Do not place Type A joints more than 100 ft. apart for proper joint performance. Note roadway width as nominal in Plan view and Typical Section for 24-, 28-, and 30-ft. roadway structures. Overall width in Plan view and Typical Section must be shown as actual overall width for example, 32.334 ft. for 30-ft. roadway structures. Guide to Bridge TxDOT 03/2016 22
Pretensioned Concrete Spread Box Beams (X-Beams) Bridge Advantages/ Usefulness Pretensioned concrete X-beams are useful for bridges requiring shallow superstructures and where future widening is anticipated. Pretensioned concrete X-beam bridges are predicted to cost more than pretensioned concrete I-Girder bridges but less than conventional pretensioned concrete box beam bridges. Construction is similar to pretensioned concrete I-Girder bridges. Drawing Location Drawing Features Needed for XB prefixes. Web site: http://www.dot.state.tx.us/insdtdot/orgchart/cmd/cserve/standard/bridgee.htm#xbeams Designed for HL93 live load in accordance with AASHTO LRFD Bridge Design Specifications. Accommodate: Four beam depths (20-, 28-, 34-, and 40-in.), each in two nominal widths (4-ft. and 5-ft.). Only 5-ft. wide beams are used with the standard roadway widths. 32-, 38-, 40-, and 44-ft. roadway widths 0-, 15-, and 30-degree skew angles. Span lengths of 40-ft. through 110-ft., in 5-ft. increments. Not all beam types accommodate all span lengths. Abutment header slopes of 2:1 and 3:1. Most standard rail types. Roadway surface is a cast-in-place concrete slab with 8-inch depth. Details are provided to construct 2- or 3-span units with slabs continuous over interior bents. Using units reduces the number of expansion joints. support these foundation options: Drilled shafts (36-in) Multi-pile footings Prestressed concrete piling (16-, 18-, 20-,24-in) Steel H-piling (14x73, 14x117, 18x135) Nine standard drawings are provided to use with customized bridge plans. XBSD Roadway-specific Prestressed Concrete X-Beam Design standard drawing AXB Roadway and skew-specific Abutment standard drawing Guide to Bridge TxDOT 03/2016 23
(Continued) Needed for Additional Needed to Complete Restrictions on Use of BXB or BTXB Roadway and skew-specific Interior Bent standard drawing or for interior Trestle Bents SXB Roadway and skew-specific span standard drawing Beam depth-specific Prestressed Concrete X-Beam Details standard drawing (XB20, XB28, XB34, or XB40). XBBR-MS Minimum Erection Bracing Requirements with Miscellaneous Slab Details standard drawing. XBCS Continuous Slab details standard drawing. (Only if using multispan unit with slab continuous over interior bents). XBEB Elastomeric Bearing standard drawing XBTS Thickened Slab End Details standard drawing Bridge Layout Summary of Estimated Quantities (if not shown on Bridge layout). Drawing with bearing seat elevations. (Recommended, see Special Considerations ). Expansion joint detail drawings Bridge railing detail drawings BAS-A or BAS-C Bridge Approach Slab drawing, if applicable. BMCS Bridge Mounted Clearance Sign standard drawing, if applicable. BL Bridge Lighting standard drawing, if applicable. BPBW Bridge Protective Beam Wrap, if applicable. CP Prestressed Concrete Piling standard, if piling is used for foundations. CRR Concrete Riprap and Shoulder Drain standard drawing, if applicable CSAB Cement Stabilized Abutment Backfill standard drawing, if applicable. FD Common Foundation Details standard drawing ODSR Optional Drilled Shaft Reinforcing standard drawing. Verify applicability prior to use. PBC-RC or PBC-P Precast Bent Cap Option standard drawing. Use (RC) for round columns and (P) for piles. PCP and PCP-FAB Prestressed Concrete Panel standard drawings PMDF Permanent Metal Deck Form standard drawing SRR Stone Riprap, if applicable. XBSK - X-Beam Shear Key standard drawing, if applicable SSPC Steel Sheet Piling Corner Details standard drawing, if applicable Do not change roadway cross slope on bridges and do not allow roadway vertical curves on bridges with skewed supports. These two restrictions are to simplify calculations for bearing seat elevations. Skew angle is limited to 30 degrees. Do not change beam type (for example, Type 5XB20 to 5XB34) within a bridge; transition bent details are not provided. Guide to Bridge TxDOT 03/2016 24
(Continued) Restrictions on Use of Maximum allowed column height, allowed exposed pile heights, and maximum allowed pile loads are listed on bent details. Do not use rail types T66, T80HT, T80SS, C412, C66, or T224. Their width or weight precludes their use on standard roadway width spans. Use issued substructure details only with issued span details. The maximum number of spans per unit is three. The maximum unit length cannot exceed the limits shown on standard drawing XBCS. Some unit lengths are too great to use sealed or open armor joints and Type A joints. Do not change skew angle within a bridge. Do not use single-sided crash cushions (see Design Division standard drawing SSCC-03A) with abutment wingwall lengths less than 7 ft. do not accommodate raised sidewalks and medians or rails not on edge of slab. If adding a raised sidewalk, median or rail, check standard drawing for additional loading. Note: Some restrictions may be overcome by modifying the standard drawings with appropriate additional details and information. Denote modified details as MOD in the title block, and clearly indicate which details were modified in the standard drawing sheet. All modified standard drawings must be signed, sealed, and dated by a registered Professional Engineer. Special Considerations Provide bearing seat elevations in the plans. The bearing seats are sloped with the roadway cross-slope along the bent, not level, and two elevations left side and right side need to be provided for each bearing seat. If an adjustment is made to the section depth (to accommodate a sag vertical curve, for example), it is recommended to note the section depth adjustment used along with the bearing seat elevations. Spreadsheet STD-BRG.xls, available from the Bridge Division, is a tool to help calculate and generate bearing seat elevations and bearing pad tapers. If the presence of a roadway vertical curve forces a haunch depth greater than 3.5-in at any point on a beam, standard drawing XBBR-MS instructs the contractor to reinforce the haunch. If prestressed concrete panels are used as a forming option, this haunch reinforcement is shown on standard drawing PCP. Do not use open bridge rails--such as T223, T552, etc. when frequent use of de-icing agents is anticipated. If deck drainage is desired and de-icing agent use is predicted, use the drain details shown on standard drawing XBBR-MS. Locate the drain locations on the Bridge Layout (no closer than 4 ft. from centerline of substructure caps). Adjust bent concrete quantities as needed for column heights shown on the Bridge Layout. Adjust abutment concrete quantities if not using approach slabs. See substructure standard drawings for guidance. Guide to Bridge TxDOT 03/2016 25
(Continued) Special Considerations Specific Bridge Layout Requirements On substructure standard drawings, dowel bars D are noted to be excluded at ends of units. Therefore, if continuous slab units are indicated on the Bridge Layout and standard drawing XBCS is included in the plans, do not use dowels at unit ends (expansion joint locations). Quantities provided for reinforcing steel weight and slab concrete volume are not bid items. They are provided for Contractor s information only. Label all beam ends with a D, except when using multi-span units. With units, do not label beam ends D at expansion joint locations. List unit lengths, if not locating expansion joints at each bent. For continuous slabs, see details and notes on span standard drawings and standard XBCS; two- or three-span units are conditionally permitted. Verify that column heights do not exceed values listed on bent standard drawings. These maximum heights must be evaluated by the Engineer in areas of soft soil or where scour is anticipated. Indicate abutment wingwall foundations, if required. See Abutment standard drawings for wingwall foundation requirements, based on beam type and header slope. Recommended expansion joints in order of preference are 4-in. sealed expansion joints (see standard drawing SEJ-A) and sealed armor joints (see standard drawing AJ), and Type A joints (see standard drawing XBBR- MS). Type A joints and open armor joints are not recommended for On- System structures. Type A joints are recommended for bridges with low traffic volumes only. Do not place Type A joints more than 100 ft. apart for proper joint performance. Guide to Bridge TxDOT 03/2016 26
Cast-in-Place Concrete Slab and Girder (Pan Form) Bridge Advantages/ Usefulness The primary advantage of concrete slab and girder span bridges is their ease of construction. Primary disadvantages are geometric restrictions imposed by the fixed-dimension steel forms used to construct this bridge type s spans. This bridge type is referred to as a pan form, a pan girder, or CG spans. State-wide, concrete slab and girder span bridges are more expensive than pretensioned concrete I-girder bridges but can be economical with the right conditions. Drawing Location Drawing Features Needed for CG prefixes. Web site: http://www.dot.state.tx.us/insdtdot/orgchart/cmd/cserve/standard/bri dge-e.htm#panform Designed for HL93 live load in accordance with AASHTO LRFD Bridge Design Specifications. accommodate 24 ft. roadway width The following skew angles: 0 degrees 14 degrees, 2 minutes 26 degrees, 34 minutes 36 degrees, 52 minutes 45 degrees Two span lengths, 30 ft. 4 in. and 40 ft. 0 in., with superstructure depths of 24 in. and 33 in., respectively. Span lengths increase modestly with skewed supports (see Special Considerations) Transition bents Most standard rail types. Abutment header slopes of 2:1 and 3:1 support these foundation options: Drilled shafts (24-in) Prestressed concrete piling (16- and 18-in) Steel H-piling (HP14x73 and HP14X117) ACG Roadway and skew-specific Abutment standard drawings BCG Roadway and skew-specific Interior Bent standard drawing BCGT Transition Bents standard drawing, if applicable CG Roadway and skew-specific Span or Unit standard drawing Guide to Bridge TxDOT 03/2016 27
(Continued) Needed for Additional Needed to Complete Restrictions on Use of CG-MD Miscellaneous Details for Concrete Slab and Girder Spans standard CGRAD Rail Anchorage Details for Concrete Slab and Girder Spans standard drawing Bridge Layout Summary of Estimated Quantities (if not shown on Bridge Layout). Bridge railing detail drawings. Expansion Joint detail drawings. BAS-A or BAS-C Bridge Approach Slab standard drawing, if applicable. CP Prestressed Concrete Piling drawing, if piling is the foundation type. CRR Concrete Riprap and Shoulder Drains standard drawing, if applicable. CSAB Cement Stabilized Abutment Backfill standard drawing, if applicable FD Common Foundation Details standard drawing ODSR Optional Drilled Shaft Reinforcing standard drawing. Verify applicability prior to use. SRR Stone Riprap, if applicable. SSPC Steel Sheet Piling Corner Details standard drawing, if applicable Do not change standard span lengths without changing bent cap width. The two standard span lengths are based on the span s fixed length steel forms fitting between 24-in. wide substructure caps. The only skews available are those listed on the span standard drawings. This constraint is due to steel form assembly restrictions. Do not change skew angle within a bridge. Maximum allowed slab overhang is 13.75 in. Maximum allowed column height, allowed exposed pile heights, and maximum allowed pile loads are listed on bent details.. Do not use a rail type that is not listed on the CGRAD standard drawing. Do not use multi-pile footings shown on standard drawing FD. Use issued substructure details only with issued span details. Do not use single-sided crash cushions (see Design Division standard drawing SSCC-03A) with abutment wingwall lengths less than 7 ft. Do not use rail types T66, T80HT, T80SS, C412, C66, or T224. Their width or weight precludes their use on standard roadway width spans. do not accommodate raised sidewalks and medians or rails not on edge of slab. If adding a raised sidewalk, median or rail, check standard drawing for additional loading. NOTE: Some restrictions may be overcome by modifying the standard drawings with appropriate additional details and information. Denote modified details as MOD in the title block, and clearly indicate which details were modified in the standard drawing sheet. All modified standard drawings must be signed, sealed, and dated by a registered Professional Engineer. Guide to Bridge TxDOT 03/2016 28
Special Considerations Adjust bent concrete quantities as needed for column heights shown on the Bridge Layout and for transition bents. Adjust abutment concrete quantities if not using approach slabs. See substructure standard drawings for guidance. Spreadsheet STD-BRG.xls, available from the Bridge Division, is a tool to help calculate and generate top of cap elevations. Slab concrete is paid by the cubic yard of Concrete Pan Girder. Actual lengths of spans on skewed supports are longer than nominal span lengths (30 ft. 4 in. and 40 ft. 0 in.) because of steel form assembly requirements. Bent stations and span lengths shown on bridge layouts should reflect actual span lengths, which can be found for each skew on the span standard drawings. drawing CG-MD provides guidance and restrictions on locating expansion joint locations on the bridge layout. 4-in. x 3/8-in. expansion joint material placed on the top corners of all substructure caps (see standard drawing CG-MD for details) prevents spalling of cap concrete due to span rotation, deflection, and expansion. Never use dowels Q, shown on standard drawing CG-MD, on both sides of a cap at fixed bent locations. Windows in the bottom of span end diaphragms are required at all expansion joint locations (see standard drawing CG-MD) to help water and debris exit between span ends. Sealed expansion joints (see standard drawing SEJ-A) and sealed armor joints (see standard drawing AJ) are recommended with this structure type. If 18-in prestressed concrete piling is used, the piling will probably need to be broken back to fit in substructure caps. See piling standard drawing for break-back details. Do not use open bridge rails such as T223, T552, etc. when frequent use of de-icing agents is anticipated. Specific Bridge Layout Requirements In the Elevation view, indicate support condition at each bent for example, E or F. See standard drawing CG-MD for more information. In the Plan view, indicate expansion joint type at each bent that is labelled E in Elevation. Verify that column or exposed pile heights do not exceed values listed on bent standard drawings. These maximum heights must be evaluated by the Engineer in areas of soft soil or where scour is anticipated. Guide to Bridge TxDOT 03/2016 29
Cast-in-Place Concrete Slab Span Bridge Advantages/ Usefulness Cast-in-place concrete slab span bridges have shallower superstructures than any other bridge for which TxDOT standard drawings exist. Cast-in-place concrete slab span bridges have short span lengths. Cast-in-place concrete slab span bridges have comparable cost to concrete slab and girder (pan form) bridges. Drawing Location Drawing Features Needed for Additional Needed to Complete (Continued) CS prefixes. Web site: http://www.dot.state.tx.us/insdtdot/orgchart/cmd/cserve/standard/bri dge-e.htm#slabspans Designed for HL93 live load in accordance with AASHTO LRFD Bridge Design Specifications. accommodate 24-, 28-, 30-, 38-, and 44-ft. roadway widths. 0-, 15-, and 30-degree skew angles provide a 14-in slab depth with a two-span (each 25ft) unit and with three-span (each 25 ft.) unit. provide a 16-in.slab depth with a simple span (25ft) and with a three-span (25 ft., 30ft., and 25 ft.) unit. Abutment header slopes of 2:1 and 3:1 Most standard rail types. support these foundation options: Drilled shafts (24-in) Prestressed concrete piling (16-and 18-in.) Steel H-piling (HP14x73 and HP14x117) ACS Roadway and skew-specific Abutment standard drawing. Some skewed abutment standard drawings are foundation-specific (for example, for drilled shafts and pilings). BCS - Roadway and skew-specific Interior Bent standard drawing CS Roadway and skew-specific Span or Unit standard drawing CS-MD Miscellaneous Details for Cast-in-Place Concrete Slab Span standard drawing. Bridge Layout. Summary of Estimated Quantities (if not shown on the Bridge Layout). Bridge railing detail drawings BAS-A or BAS-C Bridge Approach Slab standard drawing, if applicable Guide to Bridge TxDOT 03/2016 30
Additional Needed to Complete Restrictions on Use of CP - Prestressed Concrete Piling standard drawing if pilling is the foundation type. CRR - Concrete Riprap and Shoulder Drains standard drawing, if applicable. CSAB Cement Stabilized Abutment Backfill standard drawing, if applicable. FD Common Foundation Details standard drawing ODSR Optional Drilled Shaft Reinforcing standard drawing. Verify applicability prior to use. SRR Stone Riprap, if applicable. SSPC Steel Sheet Piling Corner Details standard drawing, if applicable. Do not change slab depth (for example, 14-in. to 16 in) within bridges; transition bent details are not provided. Skew angle is limited to 30 degrees. Do not change skew angle within a bridge. Maximum allowed column height, allowed exposed pile heights, and maximum allowed pile loads are listed on bent details. Do not use rail types T66, T80HT, T80SS, C412, C66, or T224. Their width or weight precludes their use on standard roadway width spans. Do not use multi-pile footings shown on standard drawing FD. Use issued substructure standard drawings only with issued span standard drawings. Do not use open armor joints; no mechanism for draining silt and other debris from joints and substructure caps exists with armor joints or any other open joint. Do not use single-sided cushions (see Design Division standard drawing SSCC-03A) with abutment wingwall lengths less than 7 ft. do not accommodate raised sidewalks and medians or rails not on edge of slab. If adding a raised sidewalk, median or rail, check standard drawing for additional loading. NOTE: Some restrictions may be overcome by modifying the standard drawings with appropriate additional details and information. Denote modified details as MOD in the title block, and clearly indicate which details were modified in the standard drawing sheet. All modified standard drawings must be signed, sealed, and dated by a registered Professional Engineer. Special Considerations Use 16-in. deep slab span details for only a one-span bridge or a bridge needing a 30-ft. span as part of a three-span (25-ft., 30-ft., and 25-ft.) unit. Otherwise, the drawings accommodate any number of spans greater than one with span details for a 14-in. deep slab. (Continued) Adjust bent concrete quantities as needed for column heights shown on Guide to Bridge TxDOT 03/2016 31
Special Considerations Specific Bridge Layout Requirements the Bridge Layout. Adjust abutment concrete quantities if not using approach slabs. See substructure standard drawings for guidance. Slab concrete is paid by the cubic yard of Class S Concrete (Slab). Actual span lengths for spans on supports skewed 30 degrees are 0.5 ft. longer than nominal span length. This allows the same length bar joist to support slab formwork regardless of skew. Bent stations and span lengths shown on bridge layouts should reflect actual span lengths. Spreadsheet STD-BRG.xls, available from the Bridge Division, is a tool to help calculate and generate top of cap elevations. Skewed substructure caps are deeper than non-skewed caps to accommodate shear keys formed into the tops of skewed caps. A bent with a FIX expansion condition may support two simple spans. drawing CS-MD provides guidance and quantity adjustments for use of this condition. Only one of these spans may be anchored to the bent with Dowels Q (shown on this standard drawing and bent standard drawings) to prevent spalling of cap concrete. To prevent spalling of cap concrete due to span rotation, deflection, and expansion, 4-in. by 1/4-in. preformed bituminous fiber material is placed on the top corners of all substructure caps. See standard drawing CS-MD for details. drawing CS-MD provides a detail allowing approach slabs to be cast to the top of abutment caps. Type A expansion joints are the only expansion joints supported for these standard drawings. The small thermal movements expected from cast-in-place slab construction do not justify the cost of using strip seal expansion joints (see standard drawing SEJ-A). Type A expansion joints, detailed on span standard drawings, are not paid for directly but are considered subsidiary to Item 422, Concrete Superstructures. Do not use open bridge rails such as T223, T552, etc. when frequent use of de-icing agents is anticipated In the Elevation view, indicate fixity at each bent (EXP or FIX). Use standard drawing CS-MD for assistance. In the Plan view, indicate Type A expansion joint at each bent labelled EXP in the Elevation view. Verify that column or exposed pile heights do not exceed values listed on bent standard drawings. These maximum heights must be evaluated by the Engineer in areas of soft soil or where scour is anticipated. Guide to Bridge TxDOT 03/2016 32
Steel Beam Bridge Advantages/ Usefulness Steel beams are useful for bridges requiring shallow superstructures, bridges where future widening is anticipated, and bridges where crane weight, capacity, and location are issues. Steel beam bridges are cost comparable to pretensioned concrete box beam bridges. Construction is similar to pretensioned concrete I-Girder bridge construction. Drawing Location Drawing Features Needed for SB prefixes. Web site: http://www.dot.state.tx.us/insdtdot/orgchart/cmd/cserve/standard/bri dge-e.htm#steelbeams Designed for HL93 live load in accordance with AASHTO LRFD Bridge Design Specifications. accommodate 24-, 28-, and 30-ft. roadway widths. 0-, 15-, and 30-degree skew angles. Eight rolled beam types (W18, W21, W24, W27, W30, W33, W36, and W40). Optional plate girders for each rolled beam Weathering and painted steel Span lengths of 30 ft. through 120 ft., in 5 ft. increments. Not all beam types accommodate all span lengths. Abutment header slopes of 2:1 and 3:1. Most standard rail types. Roadway surface is a cast-in-place concrete slab with 8-in. depth. Details are provided to construct 2- or 3-span units with slabs continuous over interior bents. Using units reduces the number of expansion joints. support these foundation options: Drilled shafts (30-in) Prestressed concrete piling (16-, 18-, and 20-in.) Steel H-piling (HP14x73 and HP14x117). Pile bents are not available for all span and roadway combinations. drawings are not provided for use with customized bridge plans. SBSD Roadway specific Steel Beam Design standard drawing. ASB Roadway and skew-specific Abutment standard drawing. BSB Roadway and skew specific Interior Bent standard drawing. Guide to Bridge TxDOT 03/2016 33
(Continued) Needed for Additional Needed to Complete Restrictions on Use of SSB Roadway and skew specific span standard drawing. SBBR Erection and Bracing Requirements standard drawing. SBCS Slab details standard drawing. Continuous Slab details standard drawing SBCS (only if using multi-span units with slab continuous over interior bents). SBEB Elastomeric Bearing standard drawing. SBMD Steel Beam Miscellaneous Details standard drawing. SBMS Steel Beam Miscellaneous Slab Details standard drawing. SBTS Steel Beam Thickened Slab End Details standard drawing. Bridge Layout Summary of Estimated Quantities (if not shown on Bridge Layout). Drawing with bearing seat elevations (Recommended, see Special Considerations ). Bridge railing detail drawings. Expansion joint detail drawings. General notes that specify whether the steel is to be painted. BAS-A or BAS-C Bridge Approach Slab standard drawing, if applicable. BL Bridge Lightning standard drawing, if applicable. BMCS Bridge Mounted Clearance Sign standard drawing, if applicable CP Prestressed Concrete Piling standard drawing. CRR Concrete Riprap and Shoulder Drain standard drawing, if applicable. CSAB Cement Stabilized Abutment Backfill standard drawing, if applicable. FD Common Foundation Details ODSR Optional Drilled Shaft Reinforcing standard drawing. Verify applicability prior to use. PBC-RC or PBC-P Precast Bent Cap Option standard drawing. (RC) for round columns or (P) for piles. PCP &PCP-FAB Prestressed Concrete Panel standard drawings PMDF Permanent Metal Deck Form standard drawing SRR Stone Riprap, if applicable. SSPC Steel Sheet Piling Corner Details standard drawing, if applicable. Do not change beam type (such as W18 to W21) within a bridge; transition bent details are not provided. Do not change skew angle within a bridge. Maximum allowed column height, allowed exposed pile heights, and maximum allowed pile loads are listed on bent details.. Do not use rail types T66, T80HT, T80SS, C412, C66, or T224. Their width or weight precludes their use on standard roadway width spans. Do not use multi-pile footings shown on standard drawing FD. Use issued substructure details only with issued span details. Guide to Bridge TxDOT 03/2016 34
(Continued) Restrictions on Use of The maximum number of spans per unit is three, and maximum unit length must not exceed three times the length of the shortest end span. For example, a two-span unit with span lengths of 30 ft. and 60 ft. is acceptable, but a two-span unit with span lengths of 50 ft. and 115 ft. is not. Do not use single-sided crash cushions (see Design Division standard drawing SSCC-03A) with abutment wingwall lengths less than 7 ft. do not accommodate raised sidewalks and medians or rails not on edge of slab. If adding a raised sidewalk, median or rail, check standard drawing for additional loading. NOTE: Some restrictions may be overcome by modifying the standard drawings with appropriate additional details and information. Denote modified details as MOD in the title block, and clearly indicate which details were modified in the standard drawing sheet. All modified standard drawings must be signed, sealed, and dated by a registered Professional Engineer. Special Considerations When selecting a beam type for a bridge, find the bridge s maximum span length on the roadway-specific SBSD standard drawing, which lists beam types along with their weight per linear foot; for example, W18x130 is a W18 beam with a weight of 130 plf. In most cases, multiple beam types are available for a given span length. If vertical clearance or hydraulic demands are not an issue, prepare the layout with the lightest beam type instead of the beam with least section depth to minimize bridge cost. Consider the whole bridge when comparing steel weights. Specify unpainted weathering steel in the plan s general notes for the least cost structure. However, avoid weathering steel if any of the following conditions exist: low steel is less than 8 ft. above normal water elevation, open armor joints are used, frequent use of de-icing agents is anticipated, or staining of riprap at embankments would be objectionable. Do not use open bridge rails such as T223 and T552 when frequent use of de-icing agents is anticipated. If deck drainage is desired and deicing agents use is predicted, use the drain details shown on standard drawing SBMS. Locate these drains on the Bridge Layout (no closer than 4 ft. from centerline of substructure caps). Refer to the Table of Maximum Allowable Exposed Pile Heights and Pile Loads and the Table of Foundation Loads on the Interior Bents standard drawing when sizing piles for the Bridge Layout. Some roadway/span combinations cannot use pile bents. All beams and optional plate girders are specified to be cambered for total dead load deflection. Optional plate girders are specified to have additional camber for any crest roadway vertical curve. If a sag roadway vertical curve is located on the span, the top-of-slab to top-of-beam Guide to Bridge TxDOT 03/2016 35
(Continued) Special Considerations Specific Bridge Layout Requirements dimension at centerline of bearings may need adjustment. To accommodate a sag vertical curve, once beyond the thickened slab ends reduce the 2-in. haunch on top of the beam to 0.5 in. with prestressed panels and to 0.0 in. with permanent metal deck forms. Bearings for exterior beams have anchor bolts located on the fascia side of the beam for restraint of lateral and uplift forces. Each span has four anchor bolts. Anchor bolts use an epoxy anchorage system; they are not cast-in-place. It is acceptable to cut through substructure reinforcement when coring holes for the anchor bolts as structural demands on this reinforcement are limited at anchor bolt locations. A slab thickness tolerance of +1 in., 0 in. is specified. Dead load deflections for steel beams are more sensitive to fluctuation in slab thickness than for prestressed concrete beams. Quantities provided for reinforcing steel weight and slab concrete volume are not bid items. They are provided for Contractor s information only. Bearing seat elevations should be provided in the plans. Although not required, bearing seat elevations facilitate shop drawing review as beam slopes can be readily obtained from bearing seat elevations. If an adjustment is made to the section depth to accommodate a sag vertical curve, note the section depth adjustment along with the bearing seat elevations to prevent modification of the span standard drawings. Spreadsheet STD-BRG.xls, available from the Bridge Division, is a tool to help calculate and generate bearing seat elevations. It also generates girder slopes, which can be provided with the bearing seat elevations to aid the bearing pad fabricator. Adjust bent concrete quantities as needed for columns heights shown on the Bridge Layout. Adjust abutment concrete quantities if not using approach slabs. See substructure standard drawings for guidance. Indicate beam type, for example, W18 or W21. Use only one beam type for a bridge. See Special Considerations for help in selecting a beam type. List unit lengths if not locating expansion joints at each bent. For continuous slabs, see details and notes on span standard drawings and standard SBCS; two- or three-span units are permitted. Indicate abutment wingwall foundations, if required. See Abutment standard drawings for wingwall foundation requirements, based on beam type and header slope. Verify that column or exposed pile heights do not exceed values listed on bent standard drawings. These maximum heights must be evaluated by the Engineer in areas of soft soil or where scour is anticipated. Recommended expansion joints in order of preference are 4-in. sealed expansion joints (see standard drawing SEJ-A) and sealed armor joints (see standard drawing AJ). Open armor joints are not recommended. Do not place sealed armor joints more than 150 ft. apart for proper joint performance. Guide to Bridge TxDOT 03/2016 36